The present invention relates to an electrical connection box for housing a circuit board on which an electrical circuit such as a power supply circuit is mounted.
In general, a circuit board including an electrical circuit such as a power supply circuit is installed in a vehicle with a box housing the circuit boards. In this case, when the circuit board includes a large-current electrical circuit such as a power supply circuit having a large calorific value, the radiation performance of the box should be enough large.
As a countermeasure for radiating the heat produced from the large-current electrical circuit, a related-art electrical connection box hag a cooling structure is provided (for example, Japanese Patent Publication No. 2001-119838A).
As shown in FIG. 5, in the related-art electrical connection box, a plurality of substrates 2 having a metal core is housed within a housing including a plurality of cases 1. The related-art electrical connection box has a structure in which a heat radiation fin 5 is attached to a printed substrate 2 through a thermal conductive insulation sheet 3 and a metal spacer 4 which are interposed therebetween, a heat pipe 6 is attached to the printed substrate 2 through the thermal conductive insulation sheet 3 interposed therebetween, and the heat pipe 6 is connected to a body panel of a vehicle, thereby radiating heat from the housing.
However, in the related-art electrical connection box, since it is necessary to connect the heat pipe 6 to the body panel of the vehicle so as to radiate heat from the housing, the attaching position in the vehicle is limited.
Since the thermal conductive insulation sheet 3, the radiation fin 5 having a complicated shape, and the heat pipe 6 are needed for the radiation structure, the structure size is increased, thereby causing an increase in size of the electrical connection box and a rise in cost.
When the electrical connection box is dismantled, the thermal conductive insulation sheet 3, the radiation fin 5, and the heat pipe 6 should be detached from the substrate 2. As a result, a great effort is required for the dismantling.